I like this subversion in how his attitude is unchanged in the new revelation of Shy's powers.
Usually, when a newbie/weak hero(ine) shows off their new skill, the cold hard-as-nails teacher is slightly impressed, cracks a rare smile, admits there's potential, et cetera. Take Aizawa-sensei from MHA. We all know the scene: Midoriya doesn't impress him with the new 'Super Power' Quirk he has and how it destroys his arm. When Midoriya uses only his finger instead of his whole arm, Aizawa is rather impressed with this and doesn't expel him from UA.
But Kira here? No, his reaction is a mere "Oh. Okay. You can use fire." and continues beating her down as if nothing happened. He's hardly fazed by revelations, and even during the Heroic BSoD(?) he isn't shaken enough for her to get a good hit him and shock him. I don't know why, but the fact that he's tougher than the tough guys really appeals to me.